An explicit derivation of the Mobius function for Bruhat order

Abstract

We give an explicit nonrecursive complete matching for the Hasse diagram of the strong Bruhat order of any interval in any Coxeter group. This yields a new derivation of the Mobius function, recovering a classical result due to Verma.

9 pages; final version

References in corpus (2)

• The sorting order on a Coxeter group
• Discrete Morse theory for totally non-negative flag varieties